reference to entity %1 for which no system identifier could be generated

Cause:

This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.

Example:

textexample textexample

Bad:
textexample textexample
Good:
textexample textexample

Solution:

textexample textexample

References: